Abstract:

The present invention relates to an arrangement (I) for transmission of
signal units to at least one receiver (3), comprising a receiving means
being arranged to receive a number of signal units within a frequency
range, whereby each signal unit includes at least one signal, and a
forwarding means being arranged to make possible for at least a portion
of said signal units to be forwarded or at least partially be blocked
with respect to said receiver (3).

Claims:

1. Arrangement (1) for transmission of signal units to at least one
receiver (3), comprising: a receiving means (9) for receiving a number of
signal units within a frequency range, whereby each signal unit includes
at least one signal, and a forwarding means (12) for making possible for
at least a portion of said signal units to be forwarded or at least
partially be blocked with respect to said receiver (3).

2. Arrangement (1) according to claim 1, characterized in that said
signal units include at least one of a time information and a secret
code.

3. Arrangement (I) according to claim 1, characterized in that it
comprises an identifying means (11), which is arranged to allocate a
unique identification to the respective signal in said signal unit.

4. Arrangement (1) according to claim 3, characterized in that said
unique identification includes at least a digital identification, whereby
said digital identification includes identifying information pertaining
to at least a time information, a secret code, signal type and frequency.

5. Arrangement (1) according to the claims 1, characterized in that one
of said signals includes a video signal and that the other signal
includes an audio signal and that said identifying means (11) is arranged
to provide said signals in said signal unit with said digital
identification that is superimposed onto the respective signal.

6. Arrangement (1) according to claim 1, characterized in that said
identifying means (11) is arranged to detect said digital identification
of each signal.

7. Arrangement (1) according to claim 1, characterized in that it
comprises a registering means (13) for including a register (17) over at
least those signal units to which said receiver (3) has authorized
access, whereby said forwarding means (12) is arranged to exclusively
forward such signal units that correspond to a corresponding stored
signal unit in said register (17).

8. Arrangement (1) according claims 7, characterized in that said
register in said registering means (13) is an active register in which it
is possible to erase stored signal units and add further signal units,
and where said register (17) is arranged such that said erasure and
addition can be affected via a communications system.

9. Arrangement (1) according to claim 1, characterized in that a unique
identity is linked to the registering means (13) which includes at least
one of an IL)-number and an ID-address, whereby said unique identity
forming a basis for which signal units that are being forwarded or
blocked by the forwarding means (12).

10. Arrangement (1) according claim 1, characterized in that said
forwarding means (12) comprises a comparator unit (16) being arranged to
compare the separated and selected signal units with said signal units in
said register (17) in the registering means (13).

11. Arrangement (1) according to the claims 10, characterized in that at
least one of said unique identification and digital identification is
arranged to make possible said comparison.

12. Arrangement (1) according to claim 1, characterized in that a
verification means (14) is arranged to verify said signal units being
forwarded by said forwarding means (12).

13. Arrangement (1) according to claim 1, characterized in that said
verification means (14) is arranged to register at least a portion of
said signal units that pass the verification means in said register (17)
in the registering means (13).

14. Arrangement (1) according to claim 12, characterized in that said
verification means (14), which includes a memory unit (18) for storing at
least those signal units to which said receiver (3) has authorized access
and which is arranged to verify that the signals being forwarded by said
forwarding means (12) correspond to a corresponding signal unit in said
memory unit (18), whereby if said forwarded signal units do not
correspond to a corresponding signal unit in the memory unit (18) the
particular signal unit is being registered by means of a specific signal
in a register unit (19).

15. Arrangement (1) according to claims 1, characterized in that stored
data in the register unit (19) are formatted to be transmitted to the
central computer (6).

16. Arrangement (1) according to claim 1, characterized in that said
receiver (3) comprises at least one of a TV-receiver, a satellite
receiver and a radio receiver.

17. Arrangement (1) according to claim 1, characterized in that it is
connected to an interface unit (8a) through which information can be
exchanged with the central computer (6) over at least one communications
network (71a, 72a, 73a).

18. Arrangement (1) according to claim 17, characterized in that it is
connected to a switch (53), which is arranged to automatically select an
interface in the interface unit (8a) that is adapted to at least one of
the communications networks (71a, 72a, 73a).

19. Arrangement (1) according to claim 1, characterized in that it is
connected to a picture telephone unit (51) through which a picture
telephone link is established between a user and at least one other user.

20. Arrangement (1) according to claim 1, characterized in that it is
included in a subscriber unit, which in turn comprises a positional
information receiver (5), whereby the positional information forms a
basis for which signal units that are being forwarded or blocked by the
forwarding means (12).

21. Arrangement (1) according to claim 1, characterized in that the
central computer (6) is arranged to include data pertaining to at least
one of the unique identity, the unique identification, the ID-number, the
ID-address and a unique address, which represents at least a subscriber,
whereby said data forms a basis for said central computer (6) to verify
whether said receiver is authorized to forward said signal units.

22. Arrangement (1) according to claim 1, characterized in that the
central computer (6) is arranged to include data pertaining to at least
one of the unique identity, the unique identification, the ID-number, the
ID-address and a unique address each representing at least a subscriber,
whereby said data forming a basis for said central computer (6) to
process said data pertaining to each users viewer surveys and statistical
investigation.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of copending U.S. patent
application Ser. No. 12/349,842, filed on Jan. 7, 2009, which claims the
benefit of the filing date and priority to U.S. patent application Ser.
No. 10/148,389, filed on May 31, 2002, which claims the benefit of the
filing date and priority to International Application No. PCT/SE00/02406
filed on Dec. 1, 2000, which claims the benefit of the filing date and
priority to Swedish Application No. 9904360-6 filed on Dec. 1, 1999. All
of the above applications are incorporated by reference in their
entirety.

THE BACKGROUND OF THE INVENTION AND PRIOR ART

[0002] The present invention relates to an arrangement for transmission of
signal units to at least one receiver.

[0003] As far as, for instance, TV-signals are concerned, these may reach
viewers via terrestrial transmitters, cable networks or satellites. Each
transmitted TV-channel comprises an image signal, a so-called video
signal and one or more sound signals, so-called audio signals and usually
a text-TV-signal. All signals are modulated onto a carrier wave, The
TV-receiver, which is connected to the TV receiver antenna receives the
signals. The channel selector in the TV-receiver, i.e. the unit for
channel tuning in the TV-receiver, tunes into a desired TV-channel, where
after the signals are detected, i.e. demodulated. The sound signal is fed
to the speaker for acoustic reproduction and the image signal is fed to a
decoder where after the image reproduction can take place.

[0004] For instance, cable TV-transmissions are encrypted, i.e. the
respective signals characteristics is altered, with the aim of preventing
unauthorised viewing, i.e. preventing image- and sound reproduction of
pay-TV-channels for which no payment has been made. In order to receive
such signal and reproduce it in a satisfactory manner the TV-receiver may
include means, such as a separate decoder being arranged to decrypt the
respective encrypted signal to its original characteristics where after
image- and sound reproduction can take place in a satisfactory manner.

[0005] However, such decoder may be manipulated, whereby the image- and
sound reproduction can take place in a satisfactory manner without a user
having paid for the TV-channel in question.

[0006] Different transmission- and reception systems for encrypted
TV-signals are known which are arranged to render unauthorised image- and
sound reproduction more difficult.

[0007] EP, A2, 0 489 385 discloses one such system. The signals are
encrypted in such manner that they cannot be received and decrypted by
means of a regular TV-receiver, but only by means of a receiver that
includes an adapted decoder, which includes a control circuit that
periodically receives a secret code from a central computer via a
telephone line, whereby the secret code is necessary for the decryption
operation. The secret code is sent according to an encrypted format and
at irregular time intervals. Furthermore, the secret code is altered with
the aim at ensuring the system's security. The secret code is transmitted
to the user under the condition that he/she has paid for a particular
channel, for instance, during a previous payment period.

[0008] The international patent application WO, A1, 97/23996 describes a
method and an apparatus for selection of programs and channels according
to a specific user's preferences with respect to, for instance, avoidance
of certain program types or specific programs. Alternatively, the user
may choose only to have particularly offensive or objectionable portions
in the programs that are transmitted to his/her receiver blocked or
substituted by alternative sound- or audio sequences. The setting of the
selection function is exclusively effected locally at the particular user
location. The user thus has full freedom to determine what should be
blocked and what should be allowed through.

SUMMARY OF THE INVENTION

[0009] The object of the present invention is to provide an arrangement by
means of which it is possible to block specific signals, such as certain
TV-signals, from a central computer, such that the signals never reach a
user's TV-receiver. Hence, the signals will not have to be encrypted with
the aim at preventing unauthorised sound- and image reproduction.

[0010] This object is achieved by the initially arrangement described that
comprises a receiving means being arranged to receive a number of signal
units within a frequency range, whereby each signal unit includes at
least one signal, and a forwarding means is arranged to make possible for
at least a portion of said signal units to be forwarded or at least
partially be blocked with respect to said receiver. The arrangement is
thus intended to be arranged between a receiver antenna and said
receiver. According to the invention, it is thereby possible to
exclusively allow those signal units to pass the arrangement that said
receiver, for instance a TV-receiver, has authorised access to.

[0011] The signal units that are received by the receiving means have
usually been passed through some kind of signal processing and been
modulated according to some kind of modulation method. However, the
receiving means that comprises a receiver includes the equipment
necessary to demodulate the signal units to baseband. The arrangement may
either process the signal units as analogue signal units or as digital
signal units. The transmitted signal units may have been sent via
telephone line, a coaxial cable, a radio connection, a satellite channel,
a radio relay system, fibre optics or a combination of some of these
physical media.

[0012] The arrangement also comprises a registering means, which in turn
includes a register over at least those signal units to which said
receiver has authorised access. The forwarding means is thereby arranged
to exclusively forward such signal units that correspond to a
corresponding signal unit in the register. Consequently, the forwarding
means compares the signal units in question with the signal units being
stored in the register. Only those signal units in question which have a
correspondence in the register are forwarded by the forwarding means. The
forwarding means may thus comprise a comparator unit being arranged to
compare the separated and selected signal units with said signal units in
the register. According to a preferred embodiment of the invention, said
unique identification is arranged to make possible said comparison. The
blocking of signal units in the forwarding means is effected
electronically and may be accomplished by different means. The signal
units may also contain or be associated with time information, whereby a
temporary availability is made possible. By indicating a start point in
time and a possible end point in time, the signal units may be allowed to
pass through the forwarding means during the interval being defined
between these points in time. However, the signal units in question are
blocked at any other time.

[0013] The register in the registering means is an active register in
which it is possible to erase stored signal units and to add further
signal units. Moreover, said register is arranged such that it is
possible to effect said erasure and said addition over a communications
system. One possibility is to realise said erasure and said addition via
a telecommunications network, whereby the arrangement may include a
modem. The arrangement thus has a unique address for said communication,
which may be encrypted. It is also possible that said erasure and said
addition takes place via, for instance, a satellite channel or a cable
network. A secret code may be sent under an encrypted format in
connection with said erasure and said addition, whereby the secret code
is necessary for said erasure respective said addition of signal units.
The erasure and the addition, of course, also involves altering of signal
units. According to an embodiment of the invention, the secret code is
changed periodically in order to ensure the security of the system. The
central computer includes a register over those unique addresses
respective codes that represent authorised users in the system.

[0014] According to an additional embodiment of the invention, the
arrangement includes a selecting means being arranged to separate and
select the received signal units from one another. This may be
accomplished by filtering. The selection means may include one or more
filters, for instance, one filter for each frequency or frequency band
which should be separated and selected.

[0015] According to an additional embodiment of the invention, at least
one of said signal units includes at least two signals, whereby said
selecting means is arranged to separate and select said signals in said
signal unit. Said signals may be a video signal and an audio signal of a
specific TV-channel, whereby said selecting means may be arranged to
separate and select said video signal and audio signal. It is thereby
possible to exclusively have the video signal forwarded by said
forwarding means, whereby said receiver, i.e. in this case the
TV-receiver, exclusively receives the video signal and thus a user only
has a possibility to reproduce the image in said TV-channel.

[0016] According to an additional embodiment of the invention, the
arrangement includes an identifying means for detecting the incoming
signal and provide at least each signal unit with a unique
identification. Preferably, said unique identification includes a digital
identification, whereby the identifying means is arranged to superimpose
the digital identification onto the respective signal unit. If the signal
unit in question includes a video signal and an audio signal, said
identifying means may be arranged to provide both said signals with a
respective digital identification that is superimposed onto the signal in
question. This identification may be allocated at transmission of a
respective signal unit, via for example a cable TV-network or a satellite
link. The identification may include information pertaining to, for
instance, signal type and frequency.

[0017] According to an additional embodiment of the invention, the
arrangement includes a verification means, which comprises a memory unit
for storing those signal units to which said receiver has authorised
access and which is arranged to verify that the signals being forwarded
by said forwarding means correspond to a corresponding signal unit in
said memory unit, whereby if said forwarded signal units do not
correspond to a corresponding signal unit in the memory unit the
particular signal unit is being registered by means of a specific signal
in a registering unit. The operation of said verification unit is thus to
investigate whether signal units leave the arrangement to which said
receiver does not have authorised access, the verification unit checks
the reliability of said forwarding means. The verification means is not
arranged to block the signal units in question that do not have a
correspondence in said memory, however said signal units are stored in
said registering unit. Said verification means may be arranged such that
all signal units that pass the arrangement are registered in the
registering unit, whereby those signal units that pass said arrangement
and are not found in said memory unit are registered together with
certain additional information. These events may, for instance, be
registered in the form of a log along with date and time information.
Furthermore, text-TV-pages that are presented in the receiver may be
registered together with page number and time of presentation (date and
time).

[0018] According to an additional embodiment of the invention, said signal
units in the registering unit are formatted to be transmitted to a
central computer. Said transmission may be effected according to various
means, whereby one possibility is that it takes place over a telephone
line, whereby the arrangement may include a modern. The arrangement
includes a computer, whereby a control unit in the computer may be
arranged such that the stored data in said registering unit are
transmitted to said central computer according to certain time intervals,
for instance once per day. In case said arrangement is arranged between a
TV-receiver antenna and a TV-receiver it is thus possible to verify, by
means of said central computer, whether a signal unit to which said
TV-receiver does not have authorised access is nevertheless received by
said TV-receiver. A software in said computer controls the registration
of signal units in said registering unit. The central computer may
re-configure the software in said computer, for instance, by remote
upgrading of the arrangement. The central computer may also control said
time intervals for transmission and the extent of the registered
information that is being transmitted.

[0019] In connection with satellite reception of TV-signals (or other
reception where an external decoder is being utilised), i.e. signal
units, in home environments it is possible to, by means of the inventive
arrangement, register for example viewer habits. By having the
verification means arranged such that all signal units that pass the
verification means are registered in the registering unit with time and
date, viewer surveys, statistical investigations etc are made possible.
The central computer includes software for receiving and processing such
registrations in a desired manner. Furthermore, multiple users may be
registered for one and the same arrangement. Each individual then togs in
to the arrangement, for instance, by entering a unique code via a remote
control, by means of voice recognition, a finger print or eye control.

[0020] According to an additional embodiment of the invention, said
receiver includes one of a TV-receiver, a satellite receiver and a radio
receiver. By radio receiver is understood a receiver being used for
wireless communication, for instance a mobile telephone.

[0021] According to an additional embodiment of the invention, the
arrangement is connected to an interface unit via which information may
be exchanged with the central computer over at least one communications
network. This network may communicate according to arbitrary standard and
utilise anyone of the access technologies known today.

[0022] According to an additional embodiment of the invention, the
arrangement is connected to a switch, which is arranged to automatically
select an interface in the interface unit that is adapted to at least one
of the communications networks.

[0023] According to an additional embodiment of the invention, the
arrangement is connected to a picture telephone unit through which a
signal being specifically directed to the receiver can be received and a
locally recorded video signal can be returned such that a picture
telephone link can be established between the user and at least one other
user.

[0024] According to an additional embodiment of the invention, the
arrangement is included in a subscriber unit, which in turn includes a
GPS receiver. The GPS receiver is arranged to convey positional
information to the central computer. The positional information may
constitute a basis for which signal units that are forwarded to the
receiver respective are blocked by the forwarding means. Typically, the
positional information can be utilised for graphical presentation of
subscriber data to the operator, for instance, on a map where each
subscriber is represented by his/her graphical position. Information and
statistics pertaining to a specific user can be presented on the map in
connection with his/her geographical position by means of a digital
graphical interface.

[0025] The positional information also gives the central computer a
possibility to determine whether the subscriber unit has been
repositioned and possibly thereby also by other means been modified in an
unauthorised way.

[0026] According to an additional embodiment of the invention, a unique
identity is linked to the registering means. On basis of this identity
signal units may either be forwarded or blocked by the forwarding means,
such that the signal units only reach the specific users, which are
indicated by the unique identity.

[0027] Depending on which type of signal units that have been received by
the arrangement according to the invention and the signal processing that
has been performed in the arrangement according to the invention, it may
be necessary to further process the forwarded signal units before
transferring them to the intended receiver.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is now to be explained by means of an
exemplary embodiment and with reference to the attached drawing, of which

[0029] FIG. 1 shows how the arrangement is arranged between a TV-receiver
antenna and a TV-receiver, and how a central computer is connected to the
arrangement,

[0030]FIG. 2 shows parts of the arrangement according to FIG. 1 and how
the signals are led through the arrangement,

[0031]FIG. 3 shows a generalisation of the arrangement according to FIG.
1,

[0032] FIG. 4 shows an exemplifying system, which includes receivers that
are connected via the proposed arrangement, and

[0033]FIG. 5 shows an embodiment, where the proposed arrangement is
included in a subscriber unit having extended communication
possibilities.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0034] FIG. 1 shows how an arrangement 1 according to the invention is
arranged between a TV-receiver antenna 2 and a TV-receiver 3 in a TV-set
4, The TV-set 4 may be of conventional type and includes a screen 5 and
the equipment necessary for i.a. the image- and sound reproduction. The
arrangement 1 makes it possible to block signal units to which the
TV-receiver does not have authorised access. It should be noted that an
arrangement according to the invention may be arranged in connection with
different types of receivers, such as satellite receivers, radio
receivers etc. Furthermore, it should be noted that the arrangement 1 is
preferably located such at a TV-viewer who uses the TV-set 4 is unaware
of the arrangement's 1 existence

[0035] The arrangement 1 includes a computer. Moreover, it is possible to
communicate with said arrangement 1 from, for instance, a central
computer 6 via e.g. a telephone line 7 which is made possible by means of
a modem 8. The power supply of said arrangement 1 can be accomplished by
various means and will not be further mentioned in this application.

[0036] The arrangement 1 includes a receiver means 9, a selecting means
10, an identifying means 11, a forwarding means 12, a registering means
13, a verification means 14 and a post processing means 15 as shown in
FIG. 2. The function of the receiving means 9, the selecting means 10,
the identifying means 11, the forwarding means 12, the registering means
13, the verification means 14 and the post processing means 15 will be
described in further detail in connection with the description of how the
signal units are led through the arrangement 1.

[0037] The TV-signals, i.e. the different TV-channels, may reach the
TV-receiver 3 via, for instance, terrestrial transmitters, cable networks
or satellites. The different TV-channels include, for example, an image
signal, a so-called video signal and one or more sound signals, so-called
audio signals and usually a text-TV-signal. All signals are modulated
onto a carrier wave. When the different signal units, i.e. the
TV-channels, reach the arrangement 1 they are received by the
arrangement's 1 receiver means 9. In the receiver means 9, which includes
a receiver, the different signals in the signal unit in question, i.e.
TV-channels, are converted to baseband. After that, the signal units in
question reach the selecting means 10 that is arranged to separate and
select the signal units in question from one another. This is
accomplished by filtering. The selecting means 10 may comprise one or
more filters, for instance, one filter for each frequency band which
should be separated and selected. In a following step the selected signal
units reach the identifying means 11, which is arranged to detect a
signal type and depending on the signal type allocate a unique
identification to the selected signal unit in question, for instance, in
the form of a digital identification being superimposed onto the signal
unit in question. This identification may be allocated initially at the
transmission of the respective signal units, via for instance, a cable
TV-network or a satellite link.

[0038] The signal units in question, that include the digital
identification, reach the forwarding means 12 in a next step. The
forwarding means 12 includes a comparator unit 16 being arranged to
compare the separated signal units in question with the contents of a
register 17 in the registering means 13. The register 17 includes those
signal units that the TV-receiver 3 has authorised access to. Only the
signal units in question that have a correspondence in the register 17
are forwarded by the forwarding means 12.

[0039] After this, the forwarded signal units reach the verification means
14. The verification means 14 includes a memory unit 18, which in
similarity with the registering means 13 includes those signal units to
which the TV-receiver 3 has authorised access. Utile signal units that
are being forwarded by the forwarding means 12 do not have a
correspondence in the memory unit 18, these signal units will be stored
along with a warning signal in a register unit 19 in the arrangement 1.
Before the forwarded signal units leave the arrangement 1 the signal
units are processed in the post processing means 15 with respect to the
TV-receiver 3,

[0040] The registering means 13 is furthermore allocated a unique identity
in the form of an ID-number and an ID-code. The unique identity offers a
possibility to arrange, group or categorise users in different ways, For
instance, it is possible to based on the unique identity and data
concerning the user, such as age, sex, civil status or occupation, send
signal units to the user that are specifically directed to users that
fulfil certain criteria, such as being male and within a particular age
interval. The software in the central computer includes means for
processing statistical data pertaining to the users plus means for
presenting the data to the operator via, for instance, a graphical
interface.

[0041] Moreover, an international employer or other larger organisation
may convey signals to a very specific and well-defined target group by
utilisation of these unique identities. All the arrangements whose ID
numbers are included in a listing in the central computer over authorised
receivers may receive the transmitted signal units, while all other
arrangements block the signal. Alternatively, ID-numbers may be allocated
according to a geographical plan such that ID-numbers within a particular
interval correspond to users within a given geographical area (a country,
a city, a region etc.). It is thereby possible to receive certain signal
units selectively within given geographical areas, which can be utilised,
for instance, by film distributors in order to avoid collision with other
media in other regions, such as cinemas. Moreover, data to be presented
via a map image can be generated. This map image may, for instance,
relate statistics and viewer habits to different geographical areas.

[0042] According to another embodiment of the invention, the transmission
of the signal units is accomplished via the Internet in the form of
Web-TV/Internet-TV (for instance via the Philips product CleverCast PC),
whereby the ID-number is linked to a particular IP-address. By utilising
this embodiment the arrangement's user is provided access to the
Internet, whereby the user, for instance, may connect to various home
pages,

[0043] It should be noted that the memory unit 18 may be left out, whereby
the verification unit 14 is arranged to compare those signal units that
pass the verification unit 14 with the signal units that are registered
in the register 17 in the registering means 13. According to another
embodiment of the invention, the verification means 14 may be located
outside the arrangement 1, whereby the order between the post processing
means 15 and the verification means 14 is reversed in relation to what is
shown in FIG. 1,

[0044] The arrangement 1 may, for instance, be placed centrally in a block
of flats, while the verification means 14 may be located in direct
proximity to the respective users' TV-receivers 3.

[0045] The arrangement 1 includes a control unit 20 that is arranged such
that data being stored in the register unit 19 is transferred to the
central computer 6 at particular time intervals.

[0046] The central computer 6 may erase or add signal units to the
register 17 in the registering means 13 and in the memory unit 18 of the
verification means 14 by means of the control unit 20. All such
alterations are stored in the register unit 19 together with time- and
date information, whereby it is possible verify from the central computer
6 that the intended changes have in fact been effected as well as when
this took place.

[0047] According to an alternative embodiment of the invention, the
control unit 20 may be arranged to replace certain received signal units
with given other pre-determined signal units in the form of audio- and/or
image sequences. This is controlled by time indications being associated
to the signal units or by means of special control pulses being sent out.

[0048] Irrespective of whether the verification unit 14 is localised
internally or externally relative the arrangement 1, the registered
information is forwarded to the central computer 6, either via the
arrangement 1 or via a separate modem.

[0049] In the embodiment shown in FIG. 1 the arrangement 1 according to
the invention is connected with a central computer 6 via a modem 8 and a
telephone line 7. Naturally, it is also possible to establish a
connection between the arrangement 1 and the central computer 6 by means
of other transmission media than telephone tines. In fact, a channel for
this communication may be set up over arbitrary network or combination of
networks via which an information exchange between the arrangement 1 and
the central computer 6 can be accomplished. FIG. 3 shows a generalisation
of the assembly in FIG. 1, where the arrangement 1 is connected to a
receiver antenna 2 for reception of signal units, such as data-, radio-
or TV-signals. Furthermore, the arrangement 1 is connected to a receiver
3 for reproduction of the signals that have been received via the
receiver antenna 2. Thus, the receiver 3 is typically a radio- or a
TV-receiver, however it can naturally include an arbitrary number of
other alternative decoders for different types of signals. Instead of the
modem 8, the arrangement 1 communicates with the central computer 6 via
an interface unit 8a, which is adapted to at least one interface besides
PSTN, i.e. the regular telecommunications network for voice telephony
(PSTN=Public Switched Telephone Network). The interface unit 8a may thus
be adapted to direct communication over the Internet, via PLMN
(PLMN=Public Land Mobile Network), the electric power network, by means
of a satellite or via an equivalent public or private communications
network. This is illustrated in FIG. 3 by means of a general network 7a.
The central computer 6 is also directly, or indirectly via one or more
other networks, connected to the general network 7a. Information may
thereby be exchanged between the arrangement 1 and the central computer
6.

[0050] FIG. 4. shows an example of a system, which includes subscriber
units 41, 42 respective 43 that each comprises a receiver antenna 2, an
arrangement a receiver 3 and an interface unit 8a according to what has
been described with reference to FIG. 3 above. A satellite transmitter 44
in the system transmits signal units via a satellite 45, which preferably
is positioned in a geostationary orbit around the earth, The receiver
antenna 2 in the respective subscriber unit 41-43 is adapted to receive
the signal units that are forwarded by the satellite 45. According to a
preferred embodiment of the invention, the satellite transmitter 44 is
directly, or indirectly, connected to a central computer 6, such that
this computer can be updated with respect to which signal units
(typically channels, programs or data signals) that are sent out.
Possibly, the central computer 6 is also given a possibility to control
the transmission of signal units from the satellite transmitter via this
connection. According to the illustrated example, a first subscriber unit
41 is attached to the central computer 6 via PSTN 71a, a second
subscriber unit 42 communicates with central computer 6 at least
partially over the Internet 72a and a third subscriber unit 43 exchanges
information with the central computer 6 at least partly via a PLAIN 73a.
This PLAIN may be constituted by a mobile communications network of
arbitrary standard and access technology. It may, for instance, be a.
GSM-network (Global System for Mobile communication), a TDMA-network
(Time Division Multiple Access), a CDMA-network (Code Division Multiple
Access) or a W-CDMA-network (Wideband-CDMA), The arrangement 1 is
preferably controlled from the central computer 6 by means of control
signals being transferred via the satellite system in case of satellite
reception of signal units.

[0051]FIG. 5. shows an embodiment, where the proposed arrangement 1 is
included in a subscriber unit 50 having extended communication
possibilities. Besides the arrangement 1a. GPS-receiver 52 (GPS=Global
Positioning System) is included in the subscriber unit 50. Furthermore,
the subscriber unit 50 includes a switch 53 for effecting an automatic
choice of interface towards the central computer.

[0052] The GPS-receiver 52 registers the subscriber unit's 50 geographical
position and thereby gives an indirect indication of the position of the
receiver(s), which is(are) connected to the subscriber unit 50. The
positional information may be utilised for controlling transmission of
signal units within given geographical areas, such as a specific country,
a specific city etc. An operator can thereby be ensured that a particular
program or a particular channel cannot be received outside the desired
area of distribution. A map may be used to graphically illustrate where
the subscribers are located geographically. Each subscriber is here
represented via a mark on the map and by activation of a specific
subscriber's mark (for instance by means of an electronic pointer means,
such as a computer mouse) information and statistics pertaining to the
subscriber are presented.

[0053] The positional information may moreover be utilised by the central
computer in order to determine whether the subscriber unit 50 has been
repositioned from its original location and perhaps thereby also been
modified or transferred to another user. An updated positional
information is sent out at regular intervals, via the switch 53 and an
interface unit 8a, over a communications network to the central computer.
If the positional information would indicate a repositioning of a
particular subscriber unit 50, the central computer preferably sends out
a command to the registering means 13 in the arrangement 1 in this
subscriber unit 50, which (if the operator so desires) may result in that
the selecting means henceforth will block all received signal units.

[0054] According to a preferred embodiment of the invention, the central
computer sends a page signal to the subscriber in connection with the
effecting of such blocking. Typically, the page signal is sent out to the
subscriber (with the particular ID-number) a time period before the
moment when all received signal units are actually blocked, such that the
subscriber is given an opportunity to object against the blocking being
effected.

[0055] The UPS-receiver 52 may in additionally be used for automatic
setting of a time reference (such as a clock) in the arrangement 1.

[0056] The picture telephone unit 51 has an input for connection to a
local video signal, from for instance a picture telephone or a video
camera. A picture telephone signal may thereby be reproduced in a
TV-receiver being connected to the subscriber unit 50. A sensor 21 in the
arrangement 1 detects whether a local video signal is present on the
picture telephone unit's 51 input. If this is the case, the control unit
20 connects this signal to the receiving means 9 for further transmission
through the arrangement 1. Given that the subscriber has a picture
telephone subscription with the operator the signal may pass the
forwarding means in the arrangement 1 to the TV-receiver 3. The picture
telephone image may either be shown separately across the entire screen 5
of TV-receiver 3 or be presented in parallel with other pictorial
information in the form of, for instance, an image segment within a
larger image. According to alternative embodiments of the invention, only
one of the sound- and the image information is forwarded to the user's
receiver.

[0057] Any communication between the arrangement 1 and the central
computer is accomplished via, the switch 53 and the interface unit 8a.
The latter has, according to a preferred embodiment of the invention, at
least two alternative interfaces for communication via, at least two
different communications networks. The subscriber unit 50 may thereby
alternatively he connected to a first or at least one second
communications network. As an alternative, the subscriber unit 50 may be
simultaneously connected to at least two communications networks, such
that if a connection via a primary network is broken, a connection may be
established via, at least one secondary network. The switch 53 detects
which network(s) that is (are) connected to the interface unit 8a and
automatically controls the connection to these networks according to a
pre-determined procedure.

[0058] The present invention is not restricted to the described
embodiments, but may be varied freely within the scope of the following
claims.